Speaking on background to reporters who traveled here with Defense Secretary Robert M. Gates, the official said the consensus in a meeting today of representatives of NATO nations contributing to the effort in Afghanistan is that while rapid transition is desirable, the important thing is to get it right.

“I think there is an understandable desire that we all have to embark on transition as soon as that is feasible,” the official said, “but there was also a recognition in the session today that it should be irreversible when it is conducted –- in other words, you should not transition prematurely or you’ll have problems down the road. So I think there is a pragmatism about all of this that is reassuring.”

Dividends from successful transitions should be reinvested nearby as the effort continues, the official said. Citing the sheer size of some of Afghanistan’s provinces, he added that transition in many cases will occur at the district level, rather than at the provincial level, at first.

“In provinces like Helmand and Kandahar, there are multiple districts,” he said, “and in some cases you can transition in a district in one area, but certainly not in another area, so some of that transition dividend from that particular district would be reinvested in a contiguous district, not sent across the country.”

Transition applies not only to geographic areas, but also to institutions, the official said, and some of that already is taking place. As Afghan forces are able to take control of any given aspect of training, he explained, transition occurs. “So it’s a transition of institutions and functions, as well as geographic areas,” he said.

Although identifying Afghanistan transition progress is subject to the views of 47 contributing nations, the official said, that ideally is accomplished through “bottom-up” assessments that would enable the International Security Assistance Force Joint Command to “carry out the process of realigning the battlefield geometry” as part of its transition efforts.

Another round of assessments will take place before next month’s NATO summit in Lisbon, Portugal, the official said.

“We will also provide an overall comprehensive assessment to the secretary general and the North Atlantic Council prior to Lisbon,” he said, “and then at Lisbon we will presumably brief an assessment of where we are in the operational campaign and what the prospects are for transition.”